A needle holder presently used for suturation has the construction in which a suture needle is held in a direction at right angles to the long axis of the needle holder. Accordingly, suturation is difficult in the field of operation for deep and narrow locations. Some constructions have been proposed in order to solve this problem. However, none of them have yet been commercialized. For example, FIG. 8 and FIG. 9 show conventional deep suturers described in IKIGAKU, Vol. 158, No. 12, p. 531-532 (1988) and Japanese Utility Model Publication No. 62-32006, respectively.
First, the structure and operation of the suturer shown in FIG. 8 will be described. This suturer comprises a head portion B2 for holding a suture needle, a neck portion C2 for rotating the head portion B2 and a body portion A2 for operating the head portion B2 and the neck portion C2. These are operated by a shaft and a gear. First, by turning an operating knob 31, holding portions 36a and 36b for sandwiching the needle therebetween are opened and closed. Next, gears 40a and 40b are rotated in the same direction by engagement of a gear 41, and a pedestal bevel gear 42 on which the holding portions 36a and 36b are integrally mounted is rotated to left and right by rotating the gear 40a or 40b. The change gear 40a is slidably moved axially along a left shaft 39a into engagement with an auxiliary gear 43 meshed with the center gear 41 and changed into a gear train meshed with the right gear 40b through the auxiliary gear 43 and the center gear 41 whereby the rotational direction of the shafts 39a and 39b is reversed to give the pedestal bevel gear 42 a longitudinal rotation. Accordingly, holding and releasing of the needle are effected by turning the operating knob 31 and, next, the gear train in which the gears 40a, 40b, 41 and 43 are meshed is changed whereby lateral rotation and longitudinal bending drive of the holding portions for suturation are rendered free.
A further conventional suturer is shown in FIGS. 9(a), 9(b) and 9(c). This suturer comprises an end needle-holding portion B1 on which a suture needle is mounted, a holding portion A1 having a holder 48 and an intermediate portion C1 for connecting both B1 and A1 at opposite ends thereof. FIGS. 9(b) and 9(c) show the structure of the end needle-holding portion B1. A suture needle 44 is held so as to be sandwiched between a needle receiver 45 and a slide plate 47 which is slidably moved by a spring plate 46. The needle receiver 45 is integrally mounted on a pulley 50 rotated by a handle 48 of the holding portion A1 through wires 49a and 49b and the slide plate 47 is connected to a small handle 52 through a wire 51. By the operation of the handle 48, the suture needle is rotated for suturation through the wires 49a and 49b and the pulley 50 and, by the operation of the small handle 52, the slide plate 47 is slidably moved by the wire 51 against the spring plate 46 to hold and release the suture needle.
There are a number of problems associated with the prior art suturers. First, in the conventional example shown in FIG. 8, the drive portion is composed of a number of gears and shafts and therefore the whole device increases in dimension and cannot be inserted into a narrow incision for operation. Even if it is inserted, the suturing operation is difficult. Further, in the FIG. 9 example, interlocking between the operative handle and the rotation of the suture needle is deviated due to the slip occurring between the wire and the pulley or the sag of the wire, resulting in a difficulty of adjustment of the handle operation. In addition, it is not possible to give the suture needle a sufficient piercing force with respect to hard tissue due to slippage. Another problem is that since the rotational angle of the suture needle is small, about 90.degree., the depth of the tissue to be sutured becomes shallow, bringing forth a practical limitation.